Well, er... I don't know about the washtub bass, however if you are interested in a GARBAGE CAN BASS check out the following website:

http://www.ehhs.cmich.edu/~dhavlena/bass.htm

Be sure to check on the illustration. I tried one of these last summer and they have a great sound and are easy to play. An added advantage is that they are easier to transport especially if you have a small car. Just two days ago while I was buying "Dremel" at the hardware I checked out the garbage can section. Most likely my next project will be the Garbage Can Bass. I can use the dremel to carve something on the end of the neck.

Cap't Bob